Field of the Invention
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.
Description of the Related Art
At present, an electrophotographic photosensitive member containing an organic photoconductive material (organic electrophotographic photosensitive member, hereinafter sometimes referred to as “photosensitive member”) is in the mainstream of an electrophotographic photosensitive member to be mounted onto a process cartridge or an electrophotographic apparatus. The electrophotographic photosensitive member using the organic photoconductive material has advantages, such as a pollution-free property, high productivity, and the ease of material design.
The electrophotographic photosensitive member generally includes a support and a photosensitive layer formed on the support. In addition, the photosensitive layer is generally a laminated photosensitive layer obtained by laminating a charge generating layer and a charge transporting layer in the stated order from a support side. Further, an intermediate layer is often arranged between the support and the photosensitive layer for the purpose of suppressing the injection of charge from the support side to a photosensitive layer side to suppress the occurrence of an image failure, such as a black spot. In addition, an undercoat layer, such as an electroconductive layer, is arranged between the support and the intermediate layer in some cases.
In recent years, a charge generating material having higher sensitivity has been used. However, a rise in sensitivity of the charge generating material involves a problem in that the quantity of charge to be generated increases and hence the charge is liable to remain in the charge generating layer.
A technology involving incorporating an electron transporting material into the intermediate layer to smoothen the transfer of an electron from a charge generating layer side to the support side has been known as a technology of suppressing such remaining of the charge in the charge generating layer. In addition, in order that the electron transporting material may not be eluted at the time of the formation of the charge generating layer to be formed on the intermediate layer, when the electron transporting material is incorporated into the intermediate layer, a technology involving using a curable material, which is hardly soluble in the solvent of a coating liquid for a charge generating layer, in the intermediate layer has been known. In Japanese Patent Application Laid-Open No. 2003-330209, there is a disclosure of the incorporation of a cured product of an electron transporting material having a nonhydrolyzable polymerizable functional group into the intermediate layer.
However, the incorporation of the cured product into the intermediate layer reduces adhesiveness at an interface between the intermediate layer and the charge generating layer, and hence a ghost phenomenon is liable to occur in some cases. Accordingly, the adhesiveness is susceptible to improvement. Here, the ghost phenomenon is specifically the so-called positive ghost phenomenon in which the density of only a portion irradiated with light at the time of a forward rotation in an output image increases.